Improvement in sewing-machines



J. A. DAVlS. Sewing Machine.

No. 99,067. Patented Jany 25, 1870.

UNTTED STATES PATENT Ormea.

JOB A. DAVIS, OF WATERTOWN, NEW YORK.

IMPROVEMENT IN SEWING-MACHINES.

Specification forming part of Letters Patent No. 99,067, dated January 25, 1870; antedated January 22, 1870.

To all whom it may concern:

Be it known that I, JOB A. DAVIS, of Watertown, in the county of J eft'erson and State of New York, have invented certain Improvements in Sewing-Machines; and I do hereby declare that the following, taken in connection with the drawings which accompany and form -a new combination of parts by which the proper movement is imparted to the shuttle; and, second, in the devices which hold the shuttle and permit its proper action and allow of its ready removal.

Sewing-machinesin which aloopin g-hoop describes an elliptical path about a stationary bobbin have long been used. A machine has also been patented in which a shuttle secured to the upper end of a vertical slotted bar is driven in an elliptical path by means of a crank-pin, the bar rising and falling upon a pin. Another form of construction shows a shuttle-arm driven by a revolving crank and controlled by a single connecting-lever, whose other end is pivoted to a xed piu. In my construction,instead of pivoting such connecting-lever to a pin or pivot iixed in position, I convert the lever into a pitman or connectinglink, one end of which is connected to the revolving cra-nk and the other is connected to the free end of a rocking lever,'as hereinafter described.

Referring to the drawings, Figure l represents a side view ot' a machine with my improvements applied thereto, and Fig. 2 an end view of the same.

A is the table, and B B hangers depending therefrom to support the revolving shaft G, which receives motion by proper connections from the driving-shaft D.

E is a vertical plate, serving both as a leg or support for the table and also for a faceplate or race for the shuttle in its orbit of motion.

F is a crank-arm secured to the shaft C, and

serving by means of its revolving motion, in connection with the movements of pitman G and rocking lever H, to impart to the shuttle the requisite movements. The lever H is arranged to rock on pin or pivot I.

K is' a cradle to receive the shuttle, and it is preferably made, as shown, of a single piece of sheet metal, with appropriate ears lc 7c and vertically-projecting plate l, the latter, when the shuttle is in use, being borne upon by a spring, L, secured to the under side ot' the pitman. This cradle is attached to the pitman by a center pin, m., which admits of turning the cradle thereon as a center, as shown in red lines in Fig. 2, to facilitate the removal of or insertion of the shuttle. The cradle and the nose of the shuttle project some distance beyond the end of the pitman. The portion l is so shaped that in either position of the cradle the spring will hold it in position.

The other portions ofthe machine need not be further described.

It will now be seen that when the machine is put in motion the shuttle, while not only describing an elliptical path with its nose always toward the left side of the machine, as seen in the drawings, and also with the same threaddelivering side always uppermost to avoid the twist of the thread or the necessity of a threaddeiiector, receives a positiveness of motion in the most desirable path for taking the loop successfully, and also by means of which there is but little friction of those parts which convert the circular motion of the crank into an elliptical path for the shuttle, and hence little liability to wear and so change the course of the shuttle as to prevent its taking the loop. The true and correct conditions as to the path of the shuttle should be that when about to take the loop its point should be as near as practicable to the under side of the table and should move as nearly as can be in a horizontal line; thatythe commencement of its descent should not be until after the loop is taken, and that after the loop is taken the downward movement should be as little aspracticable, so as to create the smallest amount of slack thread. When the slotted vertical bar is employed (besides the expense of cutting the slot, which I avoid) the constant wear upon the slot and its pin soon permits alooseness and play of one upon the other, which impair their efficiency and materially change the true path of the shuttle-point While seeking to take theloop. /Vhen a single lever connected with the crank has been employed the path of the shuttle, by reason of such connection, has been in an ellipse Whose diameters are inclined nearly forty-tive degrees to the horizon, and hence the point of the shuttle, when about to take the loop of needle-thread, is directed downward from the under side of the table, and therefore cannot take it as close to the table as is bestto avoid missing :it and losing a stitch, While if its course should be reversed, so that it might attempt to take the loop While still rising, its liability to lose it Would be still greater, and it would, if successful, continue to rise unnecessarily, with a liability under any slight derangement or displacement to strike against the table and be injured and blunted.

By my construction it will be seen that the position and length of lever H is such that when the shuttle has reached a position Where it approaches the loop it lies, with pitman G, almost in a horizontal line, 'and continues about in such line until the loop is taken, and hence can take it with about the same certainty as a shuttle moving` in a straight race immediately beneath the table. It will befurther seen that its lowest point of descentis reduced to the minimum, because it is so located upon the pitman G as to be always above the outer end of crank-arm F. It Will be also seen that there is no opportunity for Variableness in the path or orbit of the shuttle, except from the-Wear ot' the pivots, which practically is inappreciable.

I claiml. The combination, with the revolving crank F, of the shuttle-carrying pitman Gr and the rocking lever H, the Whole operating substantially as described.

2. The cradle K, constructed substantially as described, and pivoted and held to the shuttie-carrier, as set forth.

JOB A. DAVIS.

Vitnesses:

JOHN H. NAPIER, G. H. WAL'rs. 

